3D printing of anisotropic Sm–Fe–N nylon bonded permanent magnets

Abstract

Fabricating a bonded magnet with a near-net shape in suitable thermoplastic polymer binders is of paramount importance in the development of cost-effective energy technologies. In this work, anisotropic Sm 2 Fe 17 N 3 (Sm-Fe-N) bonded magnets are additively printed using SmFeN anisotropic magnetic particles in a polymeric binder polyamide-12 (PA12). The anisotropic SmFeN bonded magnets are fabricated by Big Area Additive Manufacturing followed by post-printing alignment in a magnetic field. Optimal post-alignment results in an enhanced remanence of ∼0.68 T in PA12 reflected in a parallel-oriented (aligned) measured direction. The maximum energy product achieved for the additively printed anisotropic bonded magnet of Sm-Fe-N in PA12 polymer is 78.8 KJ m −3 . Our results show advanced processing flexibility with 3D printing of the development of SmFeN nylon bonded magnets designed for applications with no critical rare earth magnets.